(a) Field of the Invention
This invention relates to novel, heat-stable sweetening compositions and methods. In particular, this invention relates to a method for heat stabilizing dipeptide sweeteners which uses a polyglucose or a polymaltose. The invention also relates to a composition of a polyglucose or a polymaltose and a dipeptide sweetener, and to foodstuffs containing such a composition.
Dipeptide sweeteners are aspartyl-substituted phenylalanine compounds having many times the sweetening power of sucrose. They were discovered in the 1960's and have been developed as low calorie substitutes for sugar. They do not have a bitter aftertaste as is the case with certain artificial sweeteners.
The dipeptide sweeteners utilized in the practice of this invention are those of the type described and set forth in U.S. Pat. Nos. 3,475,403; 3,492,137; and 4,029,701, and U.S. Pat. No. 4,439,461 patented on March 27, 1984 entitled Dipeptide Sweetener Sulfate and Sulfonate Salts. In addition, several dipeptide sweetener complexes are described in U.S. Ser. No. 06/354,574 filed Mar. 4, 1982.
Despite the attractiveness of the use of these dipeptide sweeteners and their acid salts as sweeteners, they cannot be freely substituted in place of sugar for cooking or baking. It is well known that heating the free base and previously known salt forms of aspartame causes them to break down and lose their sweet taste. Consequently, they may not be useful in foodstuffs which require cooking or when mixed with food ingredients which are put through a heating process such as pasteurization.
(b) Prior Art
Dipeptide sweeteners are known in the art as described above. Polyglucose and polymaltose are described in U.S. Pat. Nos. 3,766,165 and 3,876,794. In addition, U.S. Pat. No. 3,971,857 describes a fast dissolving, low-hydroscopic, heat sensitive sweetening composition obtained by co-drying a solution of a dipeptide sweetener with a polyglucose in a ratio of 1:19 to 3:7 with a ratio of 1:3 to 1:4 being preferred, however, the patent teaches that care must be taken in drying the solution to prevent thermal decomposition.